Java is an object-oriented programming language, which means it is designed to implement object-oriented programming (OOP) concepts. Object-oriented programming is a programming paradigm based on the concept of objects, which can contain data and code, and interact with one another to achieve various functionalities. The following are the seven core OOP concepts in Java:
- Abstraction: Abstraction is the process of hiding unnecessary details from the user while showing only the essential details. It is one of the key features of object-oriented programming that helps in creating an efficient and effective software system. Abstract classes are classes that cannot be instantiated and can only be used as a base class for other classes, while interfaces define a set of methods that must be implemented by any class that implements that interface.
- Encapsulation: Encapsulation is the process of hiding the internal details of an object from the outside world. It is achieved by making the data members private and providing public methods to access and modify those data members. This ensures that the data is accessed and modified only through the methods defined by the class, which helps in maintaining the integrity of the data.
- Inheritance: Inheritance is a mechanism that allows one class to inherit the properties and methods of another class. The class that inherits the properties is called the subclass or derived class, and the class from which the properties are inherited is called the superclass or base class. In Java, inheritance is achieved using the extends keyword.
- Polymorphism: Polymorphism is the ability of an object to take on many forms. It is achieved in Java through method overloading and method overriding. Method overloading is the process of defining multiple methods with the same name but different parameters, while method overriding is the process of redefining a method in the subclass that was already defined in the superclass.
- Association: Association is a relationship between two classes where one class uses an object of another class. In Java, association is achieved by creating an object of one class inside another class.
- Aggregation: Aggregation is a special form of association where the object of one class “has a” relationship with the object of another class. In Java, aggregation is achieved by creating an instance variable of one class inside another class.
- Composition: Composition is another special form of association where the object of one class “owns” the object of another class. In Java, composition is achieved by creating an instance variable of one class inside another class, but with the added restriction that the inner class is created and destroyed along with the outer class. With the help of java training we can easily learn java core concepts for that you need to find java Training institute online or offline as per as your requirement.
In addition to these seven core OOP concepts, there are some other concepts that are also important in Java, including:
- Access modifiers: Access modifiers are keywords that are used to control the visibility and accessibility of classes, methods, and variables in Java. There are four types of access modifiers in Java: public, private, protected, and default.
- Constructors: Constructors are special methods that are used to initialize the instance variables of a class when an object is created. In Java, a constructor has the same name as the class and does not have a return type.
- Static keyword: The static keyword is used to declare a method or variable that belongs to the class rather than an instance of the class. This means that a static method or variable can be accessed without creating an object of the class.
- Final keyword: The final keyword is used to declare a variable that cannot be changed once it has been initialized. It is also used to declare a method that cannot be overridden in a subclass.
If you want to learn java you need to do some certification course in In conclusion, these are the core OOP concepts in Java that are essential for building efficient and effective software systems. Understanding these concepts is crucial for any Java developer, as they